Renal cancer accounts for more than 100,000 deaths across the world per annum. Approximately 90-95% of renal cancers arise in the renal parenchyma and are termed renal cell carcinomas. The incidence of renal cell carcinoma has been steadily rising over the past 20 years in many countries and this is thought to be only partially explained by the increased rate of incidental diagnosis (Vasudev et al., 2012)
Following surgical resection, a significant proportion of renal cancer patients will experience recurrence or present with metastatic disease at distant sites. The availability of agents directly targeting tumorigenic and angiogenic pathways has improved the outcomes of patients with advanced renal cell carcinoma (Maroto and Rini, 2014). Currently available U.S. Food and Drug Administration-approved first line targeted agents include sunitinib, pazopanib, temsirolimus, and bevacizumab (with interferon), while axitinib, everolimus, and sorafenib are most extensively used following progression as second- or third line therapy. However, all patients eventually become resistant and a substantial percentage experience immediate disease progression with first line targeted therapy. In addition, patients have variable clinical benefit and/or tolerance to different agents. Hence, the choice of therapy for an individual patient remains empiric at present.
Attempts to augment the activity of these agents by combining them together or with chemotherapy or immunotherapy have not yet proven to improve outcomes and treatment of metastatic renal cell carcinoma remains a challenge for clinicians. Thus, while current therapy has improved outcomes modestly, there remains a need to identify prognostic and predictive biomarkers that can be used to optimise treatment selection.